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A disk-and-washer (DAW) structure with biperiodic L-support was studied. Aluminum models were fabricated by calculation studies. Information for tuning the frequency was accumulated through cold model measurements. The material strength of oxygen free copper (OFC) was measured for the fabrication of the high-power model fabricated with OFC. A load test confirmed that OFC was enough sufficiently strong for this structure, although the DAW has structural complexity. On the basis of these results, eleven two-cell-units with a high-power model cavity made of OFC were fabricated. The accelerating mode and coupling mode frequencies of the entire structure were evaluated to be -1.1 MHz and -3.5 MHz, respectively, within the operating frequency of 2857 MHz, and ±2% electric field flatness was achieved. These values are sufficient for the requirements of a high-power model. A detailed design which aimed at electron acceleration was established for the DAW structure with biperiodic L-support.

A novel design for an electromagnet with a wide excitation range is described. The magnetic field distribution of an electromagnet usually deforms as the excitation approaches the saturation level. This effect can be minimized if the saturation of the ferromagnetic material is uniform; the integrated magnetic field along a flux line \intH·dsin the pole is uniform for all flux lines crossing the gap area of interest. This condition can be realized by adding vacant portions into low flux density regions in iron poles, and thus the magnetic flux density in the iron region becomes uniform. This magnetic flux density equalizer can be applied to a variety of magnets: flat dipoles, n-indexed dipoles, quadrupoles and higher-order multipole magnets.